Field
Embodiments disclosed herein generally relate to devices comprising inert carbon films. More specifically, embodiments generally relate to nanocrystalline diamond films.
Description of the Related Art
As the semiconductor industry introduces new generations of integrated circuits (IC's) having higher performance and greater functionality, the density of the elements that form those IC's is increased, while the dimensions, size and spacing between the individual components or elements are reduced. While in the past such reductions were limited only by the ability to define the structures using photolithography, device geometries having dimensions measured in um or nm have created new limiting factors, such as the conductivity of the metallic elements, the dielectric constant of the insulating material(s) used between the elements or challenges in 3D NAND or DRAM processes. These limitations may be benefited by more durable and higher hardness hardmasks.
A thick carbon hardmask is well known and commonly used as POR film. However, current carbon hardmask compositions are expected to be insufficient as DRAM and NAND continue their scaling down to under ˜10 nm regime. This downscaling will require even higher aspect ratio deep contact hole or trench etch. The high aspect ratio etch issues include clogging, hole-shape distortion, and pattern deformation, top critical dimension blow up, line bending, profile bowing are generally observed in these applications. Many etch challenges are dependent on the hardmask material property. Deep contact hole deformation is due to hardmask lower density and poor thermal conductivity. Slit pattern deformation or line bending is due to hardmask material lower selectivity and stress. So, it is desirable to have an etch hardmask with higher density, higher etch selectivity, lower stress and excellent thermal conductivity.
Nanocrystalline diamond is known as a high hardness material. Nanocrystaline diamond materials, owing to their unusual properties such as extreme hardness, chemical inertness, and high thermal conductivity, can be used for wear-resistive coatings, optical windows, surface acoustic-wave devices, and heat spreaders. However, nanocrystalline diamond films have not been applied to the semiconductor manufacture processes.
Therefore, there is a need for higher hardness films for semiconductor devices.